Portable terminals such as a portable phone and a PDA are widely in use in worldwide countries. Therefore, the character displayed on a key of the portable terminal must be printed in respective languages used in the countries. In the related art, a cover member for a push button switch is prepared for each language to be printed on a key, and is assembled and fixed to a housing of a product from a backside. The below-described Patent Document 1 discloses a technique related to a key sheet which is assembled and fixed to a housing of a product from a backside. The Patent Document 1 discloses in FIG. 5 a key sheet (11) which is assembled and fixed to a housing (101a) from a backside. The key sheet (11) is fixed to the housing (101a) with a periphery portion of a rigid resin plate (14) functioning as a so-called hook.
In addition, in the related art, a method is employed in which a hook is provided at a portion of an outer periphery of a cover member for a push button switch so that the cover member is fitted and fixed from a front side of the housing. FIG. 10 shows a well-known key frame in which a hook (projection) is provided at a portion of an outer periphery. The key frame is a member which supports a bottom portion of the cover member for the push button switch. The use of a key frame 91 having the projection 91p with a thin plate shape enables fitting, at a later time, of a cover member for a push button switch prepared for each language to a pre-assembled product, and, consequently, allows an increase in the degree of freedom in the manufacturing process.
Patent Document 1: Japanese Patent Application Laid-Open No. 2004-362891